Pileated Woodpecker With Chicks

The manifestation of such an event would be present in every facet of human existence.  For one thing crop yields would decline as insect pests devour their way through agribusiness.  Imagine the forest and their products, succumbing to insects as they chew, bore, multiply and spread disease through every leaf, bark and root therein.  The impacts would reverberate throughout life’s entire web.  Many nuts and berries would no longer be available to the mice, deer and bear.  Predators would then be starved by a paucity of prey.  Roots would no longer keep the soil stable as banks collapse to choke our streams and rivers, and on, and on – you get the point.  Of course other species might fill the gaps but diversity would suffer to the detriment of whole systems.  During spring migration, songbirds are at their best, timing the forest cleanse with the emergence of burgeoning insects.  Without this annual exodus from the southern hemisphere through our hills, swamps, forests and dales the above scenario may well unfold.

The voracious appetites of songbirds, especially the neotropical kind, can never be underestimated.  In the natural laboratory that is the Great Swamp Wildlife Refuge anyone who is diligent enough to spend an afternoon watching songbirds can testify to their prowess in the art of insect annihilation.

Downy Woodpecker With Insects

A good place to start is Pleasant Plains Road near any eastern bluebird box located prevalently in the open meadows.  Find an active box, (doesn’t have to be a bluebird, tree swallows will do just fine) and take note of the relentless activity.  Jot down the time the duration between feedings and note the types and quantities of insects provided.  I have found that the eastern bluebird during peak feeding hours brings back an average of 35 insects every twenty-five minutes.  That’s just one in the pair of adults.  When you consider both parents you get an average of 70 insects in a half hour.  Taking this out over an average June day (birds feed their young dawn till dusk) and accounting for peak and off-peak feedings, an average bluebird pair brings back 1,700 insects for fledgling consumption.  This of course does not take into consideration their own personal allowance of insect matter required for daily activities.  Take this out a step further and multiple all the other songbirds that call the swamp home in June and a much clearer perspective should emerge in regards to the medicinal value all birds have on the health of our refuge ecosystem.

This spring I was fortunate enough to spend some time with the swamp’s largest member of the woodpecker family – the Pileated (Drcoptyrus pileatus).  Finding an active cavity over a section of flooded timber was a treat, watching these magnificent birds come back to feed pterodactyl-like chicks begging from a tree hole was an absolute bonus!  Unlike the bluebird the pileated woodpecker has a much longer time between foraging and brood feeding.  The reason for this is that insect matter (mainly beetles, caterpillars and ants) are stored in their crops and regurgitated into the mouths of their hungry broods.  Both parents share the duties of feeding.  I was finding that the average duration between meals was 48 minutes.  Because the Pileated is storing prodigious quantities of food in its crop this bird is making more efficient use of its time.  This of course is a good strategy to conserve energy. Less time and energy is spent going back and forth from the cavity leaving more time to ferret out six-legged protein pills for a hungry brood.

Prothonatary Warbler With Catipillar

A common species readily observed nesting and feeding along Pleasant Plains Road this year was the Yellow Warbler (Dentroica petechia).  This neo-tropical songbird, like all members of the family Dendroica, is seemingly filled with bottomless energy supply.  Always at the nest with a caterpillar, yellow warblers make a feeding every few minutes, rarely exceeding ten minute intervals.

The efficiency in which warblers insect-glean is a thing of shear beauty and wonderment.  In the grand scheme of nature’s design these “neotrops”, as they are sometimes referred, stratify throughout the forest interior so as to lessen the effects of competition.  If you’re fortunate enough to witness a group of mixed warbler species wave through the refuge in spring you can gain a simple appreciation for the ecological importance of this guild.  Watch as blackburnian and cerulean warblers forage in the roof tops of trees at the same time common yellowthroats and Wilson warblers work in herbaceous basement of forest structure.  Prothonotary, black and white and redstart warblers can be seen at all levels but tend to hold the middle ground, leaf sweeping away the bounty of fresh hatches.

Yellow Warbler Feeding Young

This short testimony should make it clear that birds play a significant role in keeping our swamp neatly in balance with the other bio-strings attached to their behaviors.  Sadly, I report to you that two out of every three bird species are in decline worldwide, and about 11 percent of all birds are already officially threatened with extinction.  Four percent – 403 species – are “endangered” meaning they may be gone with in the blink of a human life span.  Saving large swaths of forests, wetlands and grasslands is the immediate remedy for most of them but just as important is the nurturing and restoring of the land we have already set aside.  To that end I thank all our dedicated managers, biologists and refuge staff that makes our swamp, as Thoreau would say “the sanctum sanctorum”, for all the birds that call it home.